What it is and where it fits
The Siemens 3RU1136-1JB0 is a SIRIUS thermal overload relay, size S2, designed for motor protection in control panels. It mounts directly onto a contactor via the fastening method — no separate base needed — saving rail space and wiring. The CLASS 10 trip characteristic means it will open the circuit within 10 seconds at 7.2× the set current, matching standard motor start profiles for pumps, fans, and conveyors.
Key ratings and what they mean for your panel
Rated surge voltage 6 kV gives the relay enough insulation coordination for 400 V line-to-line systems with upstream surge protection. Shock resistance of 8g / 10 ms means it holds calibration under moderate vibration — fine for floor-mounted MCCs, less so for direct engine mounting. The IP20 front protection keeps fingers and tools out but does not seal against dust or moisture; panel builders should place it inside an IP54 or higher enclosure. Mounting position is flexible: vertical surface with ±135° rotation and ±45° tilt forward/back. That covers most DIN-rail cabinet layouts without derating. Ambient operating range –20 to +70 °C with 100 % relative humidity (non-condensing) suits both heated indoor panels and unheated sheds. Screw terminals on both main and auxiliary circuits accept solid or stranded copper: main contacts up to 35 mm² (1x) or 25 mm² (2x), auxiliary contacts 0.5–2.5 mm². The AWG equivalents run 18–3 for mains and 20–14 for aux — covers typical motor leads and control wiring without adapters.